C4 - Electrochemistry

Question 1

Electrodes definition

Answer 1

Metals inserted in an electrolyte. The most commonly used are graphite, platinum and copper

Question 2

Electrolyte definition

Answer 2

An ionic compound which is decomposed by passing electric current. They can either be molten electrolytes or solutions.

Question 3

Cathode electrode definition

Answer 3

A cathode is a negative electrode. It’s an electrode where reduction takes place

Question 4

Anode electrode definition

Answer 4

An anode is a positive electrode. An anode is an electrode where oxidation takes place.

Question 5

Oxidation definition

Answer 5

The process by which oxygen is added to another substance. Oxidation is also defined as loss of electrons

Question 6

Reduction definition

Answer 6

The process by which oxygen is removed froma substance. Reduction is also defined as gain of electrons

Question 7

Electrolysis definition

Answer 7

The decomposition of an ionic compound, when molten or in aqueous solution, by the passage of an electric current.

Question 8

Electrolysis rule for cathode:

Answer 8

The ion of the least reactive will be discharged –> only one io can be discharged

Question 9

Electrolysis rule for anode

Answer 9

Is a halide is present (any atom in group 7 of the periodic table e.g. clorine), it will be discharged. If a halide isn’t present, the hydroxide ion (OH⁻) will be discharged.

Question 10

Reactivity series (10)

Answer 10

Pottasium
Sodium
Lithium
Calcium
Magnesium
Carbon
Zinc
Iron
Hydrogen
Copper